Some breaking news from Minnesota tonight. Minnesota Public Radio News reports that Senator Al Franken will announce his resignation from the Senate tomorrow. His decision comes after at least 30 Senate Democrats, including leader Chuck Schumer, today called on Franken to step down. Joining us now from the Capitol is NPR congressional correspondent Susan Davis. Hey there.

SUSAN DAVIS, BYLINE: Hey there.

KELLY: So these allegations of sexual harassment against Franken have been out there for weeks. What changed today that prompted this avalanche of Democrats to call for him to step aside?

DAVIS: Politico reported this morning about a seventh accuser. It was an anonymous woman, but she alleged that in 2006 then Al Franken, who was a comedian, not yet a senator, had - again - forcibly tried to kiss her. This is what a group of female senators, including New York Democrat Senator Kirsten Gillibrand, said for them was the tipping point. This morning, in a very rapid succession, about a half a dozen female Democratic senators put out statements calling for him to resign. And they sort of started an avalanche. From that point throughout the day, Democrats in the Senate, one after another, just started calling for Franken to resign.

I spoke to several Democratic aides who had said that this was a conversation that had been happening quietly inside the Democratic caucus for several days now but that it was just determined that it was time for him to go. I do want to add one note of caution - that the senator's office tweeted out that his final decision had not been made. He will make an announcement tomorrow. But Democrats here in the Capitol tonight certainly expect that that announcement will be his resignation.

KELLY: Now, this, of course, comes just a day after Michigan Democratic Congressman John Conyers resigned over sexual harassment allegations. Is this starting to add up to a message that Democrats are sending?

DAVIS: You know, we have to also talk about that this is happening, one, in this broader context of this national conversation, and then within politics, it's also happening as the Alabama Senate races is playing out.

KELLY: Sure.

DAVIS: And I think Democrats, particularly following President Trump's decision to re-back Roy Moore and for the Republican National Committee to get back into that race even though Moore is facing similar allegations of sexual harassment and sexual assault, Democrats want to draw contrasts. Party leaders like Nancy Pelosi are saying that they want to be a party of zero tolerance towards this kind of behavior. And I would note that it might not be over. There are two additional sitting congressmen in the House - a Republican from Texas, Blake Farenthold, and a Democrat from Nevada, Ruben Kihuen - who are facing allegations of sexual harassment, and they are also facing some calls to step aside.

KELLY: Well, other than calling for lawmakers to step aside, what else is Congress doing in response to all of these allegations? Is there some sort of legislative action, some bill brewing?

DAVIS: It's actually been quite a lot. Already both chambers in the House and the Senate have passed new rules to mandate sexual harassment training for everyone that works here, including lawmakers, once a year. They also have competing legislation that would affect both internally how sexual harassment is handled inside the Capitol. And today, Gillibrand introduced a bipartisan bill that would essentially end forced arbitration in private companies when - they say as many as 60 million Americans, when you sign up to work for a company, part of your terms of employment or that if you have a sexual harassment complaint, it has to go through a mandatory private arbitration process. They want to get rid of that.

I would note at this event today that I covered they also had former Fox News host Gretchen Carlson there to make a statement because she was one of these women, these tipping point women, that started this national conversation. So, yeah, you know, there's just - there's significant momentum, and I would say this has bipartisan support. There's a lot of Republicans in support of this legislation who want to capture this cultural moment and send a message that it's time to sort of remake how we think about the American workplace.

KELLY: And real quick, Sue, to circle you back to Al Franken - if he does say he's resigning, what happens to his seat?

DAVIS: They have a Democratic governor, it's Mark Dayton. He would get to appoint an interim senator. He's a Democrat, so there's no chance this seat will flip in the short term. Whoever that senator is will have to run for re-election in the 2018 midterms.